1. Field of the Invention
The present invention relates to a process for producing a platinum tunneling probe tip having a sharp point for use in FE-SEM, STM, and an ion beam electrode.
2. Description of the Related Art
The production of a tunneling probe tip having a sharp point by electropolishing has heretofore been conducted on tungsten, TiC, tantalum, etc. With respect to platinum, it is known that the polishing can be conducted by electrolysis with some cyanide solution (see FIG. 1).
However, with respect to the electropolishing of platinum, since the crystal grain of a platinum tunneling probe tip material is large as opposed to tungsten, TiC, tantalum, etc., the grain boundary is selectively polished, which raises problems with poor reproducibility, such as occurrence of scattering, in the shape due to the anisotropy of the crystal face with respect to the rate of polishing and difficulty in sharpening the point.